This invention is related to protection covers of tools or machines, especially a dust-proof protection cover with connecting rods.
This dust-proof protection cover is an innovative improvement of the previously designed protection cover created by the same inventor. The previous model is disclosed in Taiwan patent 152342. In that patent, the main content of design was the sliding trough (11) at the bottom board of the protection cover (10). There is also a parallel connecting shaft device (12). Such a device is made of many units of connecting shafts in the shape of X. Each unit of connecting shaft has two shafts with equal length. Two shafts are pivoted to each other at their center points in a way that the two ends of each shaft will form a pair of folded arms that will open and close. Each end of each unit of connecting shaft will connect to another pair of folded arms of another connecting shaft unit. Such a connection will form two pivot points (13). These two pivot points are inserted in a sliding trough (11) and can slide along the long axis of this sliding trough to reach the intended function of this design. (For the detailed structure and operation, please refer to the patent instruction manual. Details will not be repeated here.)
The function of this previous design was an improvement over traditional models. However, in spite of the high stability, the design still had the room for improvement. The previous design had a wider distance between the pivot point and the sliding trough to allow each pivot point (13) to move or slide smoothly within the sliding trough (11). In other words, the requirement for liberal allowance (a mechanical term) was bigger. Such a wider distance would cause each pivot point to shift or deviate within the sliding trough. Moreover, since the two pivot points in the sliding trough would shift or deviate (such as shifting to one side of the central line C or moving to both side of the central line C), sometimes two deviation values would occur during the shift. Because a dust-proof protection cover should have high precision, such deviation affects the overall operation of the protection cover. In order to reduce the degree of deviation and make the expansion and contraction of the protection cover smoother with less inaccuracy, the inventor has proposed this invention.
The purpose of this invention is to provide a dust-proof protection cover with connecting rods to reduce the degree of deviation.
In order to reach the goal described above, the dust-proof protection cover with connecting rods according to the invention has the following parts. It includes several protecting cover boards in the same shape with different sizes. The sizes of protecting cover boards are decreasing and their connection will form a structure that can expand and contract along the same axis. On each axis perpendicular to the bottom board of the protection cover, there is at least one sliding trough. In addition, there is at least a linking device made of many shafts. Each connecting shaft has two shafts with equal length. Two shafts are pivoted to each other at their center points in a way that the two ends of each shaft will form a pair of folded arms that will open and close. Each end of each unit of connecting shaft will connect to another pair of folded arms of another connecting shaft unit. Such a connection will form two pivot points. One of these two pivot points is located on the bottom cover of the protecting cover board and the other pivot point is inserted into the sliding trough of the same protecting cover board. All these connections will form a device of serial protection cover that can expand and contract.